
var JsonUti = {
	//定义换行符
	n: "\n",
	//定义制表符
	t: "\t",
	//转换String
	convertToString: function(obj) {
		return JsonUti.__writeObj(obj, 1);
	},
	//写对象
	__writeObj: function(obj //对象
		, level //层次（基数为1）
		, isInArray) { //此对象是否在一个集合内
		//如果为空，直接输出null
		if (obj == null) {
			return "null";
		}
		//为普通类型，直接输出值
		if (obj.constructor == Number || obj.constructor == Date || obj.constructor == String || obj.constructor == Boolean) {
			var v = obj.toString();
			var tab = isInArray ? JsonUti.__repeatStr(JsonUti.t, level - 1) : "";
			if (obj.constructor == String || obj.constructor == Date) {
				//时间格式化只是单纯输出字符串，而不是Date对象
				return tab + ("\"" + v + "\"");
			}
			else if (obj.constructor == Boolean) {
				return tab + v.toLowerCase();
			}
			else {
				return tab + (v);
			}
		}
		//写Json对象，缓存字符串
		var currentObjStrings = [];
		//遍历属性
		for (var name in obj) {
			var temp = [];
			//格式化Tab
			var paddingTab = JsonUti.__repeatStr(JsonUti.t, level);
			temp.push(paddingTab);
			//写出属性名
			temp.push("\"" + name + "\" : ");
			var val = obj[name];
			if (val == null) {
				temp.push("null");
			}
			else {
				var c = val.constructor;
				if (c == Array) { //如果为集合，循环内部对象
					temp.push(JsonUti.n + paddingTab + "[" + JsonUti.n);
					var levelUp = level + 2; //层级+2
					var tempArrValue = []; //集合元素相关字符串缓存片段
					for (var i = 0; i < val.length; i++) {
						//递归写对象
						tempArrValue.push(JsonUti.__writeObj(val[i], levelUp, true));
					}
					temp.push(tempArrValue.join("," + JsonUti.n));
					temp.push(JsonUti.n + paddingTab + "]");
				}
				else if (c == Function) {
					temp.push("[Function]");
				}
				else {
					//递归写对象
					temp.push(JsonUti.__writeObj(val, level + 1));
				}
			}
			//加入当前对象“属性”字符串
			currentObjStrings.push(temp.join(""));
		}
		return (level > 1 && !isInArray ? JsonUti.n: "") //如果Json对象是内部，就要换行格式化
			+ JsonUti.__repeatStr(JsonUti.t, level - 1) + "{" + JsonUti.n //加层次Tab格式化
			+ currentObjStrings.join("," + JsonUti.n) //串联所有属性值
			+ JsonUti.n + JsonUti.__repeatStr(JsonUti.t, level - 1) + "}"; //封闭对象
	},
	__isArray: function(obj) {
		if (obj) {
			return obj.constructor == Array;
		}
		return false;
	},
	__repeatStr: function(str, times) {
		var newStr = [];
		if (times > 0) {
			for (var i = 0; i < times; i++) {
				newStr.push(str);
			}
		}
		return newStr.join("");
	}
};

